The invention relates to an amphibious vehicle having wheels which can be raised, permitting the vehicle to operate on land and other bearing surfaces, and also in water, and water containing floating debris such as ice, muskeg, etc..
There are many amphibious vehicles designed to operate on land and water, and some vehicles are also designed to operate in other, soft bearing surfaces such as mud, snow, ice, muskeg, and other harsh environments. Some amphibious vehicles are fitted with wheels for use on land, and, when the vehicle is used on water, the wheels increase drag considerably and often contribute little to flotation. In some vehicles, the wheels project outwardly from sides of the vehicle, and this generally increases drag more than wheels that project below the vehicle. However, outwardly projecting wheels are desirable in some circumstances to increase stability of the vehicle on land, and also permit use of relatively wide tires to decrease ground pressure. While a decrease in ground pressure is desirable for use on soft surfaces, the loss in water performance from wide tires is usually considerable due to increased drag.
Some vehicles are self propelled, while others require towing by another powered vehicle or tractor unit, which usually is adapted to provide propulsion for the different surfaces to be encountered. One such vehicle is disclosed in U.S. Pat. Nos. 4,645,023 and 4,934,300, and is particularly adapted for use on soft surfaces e.g. ice, and snow, and also water. Such a vehicle can be used as a tug boat for towing floating barges, but such barges do not traverse land. Similarly, the potential vehicle can be used to tow sleds across snow or ice, or to tow wheeled trailers on hard surfaces, but the sleds or trailers cannot operate in water. Thus, the use of the above patented vehicle as a towing tractor is limited by load carrying trailers and the environment for which they were designed.
Consequently, there is a need for a load carrying trailer which can function in the same environment as the patented towing vehicle, that is to be able to traverse hard surfaces, soft surfaces or water, thus increasing the versatility of the combination of vehicles.